The present invention comprises a new and distinct cultivar of calla lily, botanically known as Zantedeschia sprengeri and hereinafter referred to by the cultivar name ‘Black Hero’.
‘Black Hero’ is a product of a planned breeding program, which had the objective of creating Zantedeschia hybrids for pot flower production in a wide range of colors with a large, classic flower shape. The breeding program began in 1989, and the new cultivar is a seedling selected from the crossing of a Zantedeschia sprengeri selection referred to as Z020304 (female parent, unpatented) with Zantedeschia sprengeri ‘Odessa’ (male parent, U.S. Plant Pat. No. 18,833). ‘Black Hero’ was selected in 2007 by the inventor in 't Zand, The Netherlands as one flowering plant within the progeny of the stated cross.
The first act of asexual reproduction of ‘Black Hero’ by tissue culture was performed by the inventor in September of 2011 in 't Zand, The Netherlands. Subsequent asexual reproductions by tissue culture at the same location have demonstrated that the combination of characteristics as herein disclosed for the new cultivar are retained and reproduced true to type through successive generations of asexual reproduction.
The following observations, measurements and comparisons describe plants grown in 14 cm pots in 't Zand, The Netherlands under greenhouse conditions, which approximate those generally used in horticultural practice. Color references are made to The 2001 R.H.S. Colour Chart of The Royal Horticultural Society of London, except where general color terms of ordinary significance are used.
The present invention has not been evaluated under all possible environmental conditions. The phenotype may vary with variations in environment without a change in the genotype of the plant.
The following traits have been repeatedly observed and determined to be basic characteristics of ‘Black Hero’ which, in combination, distinguish this calla lily as a new and distinct cultivar:                1. Dark purple-colored spathe; and        2. High inflorescence production.        
Further, when compared to calla lily plant named ‘Schwarzwalder’ (U.S. Plant Pat. No. 11,001), ‘Schwarzwalder’ has an upper surface spathe color of Greyed-Purple Group RHS 187A and a lower surface spathe color that varies between Greyed-Purple Group RHS 187A and Black Group RHS 202A, whereas ‘Black Hero’ has an upper and lower surface spathe color that varies between Purple Group RHS 77A and Greyed-Purple Group RHS 187A.
Table 1 provides similarities and differences of ‘Black Hero’ to its parents, Zantedeschia sprengeri selection Z020304 and Zantedeschia sprengeri ‘Odessa’.
TABLE 1‘Black Hero’SimilaritiesDifferencesZ020304White leaf spotsNumber of inflorescencesPlant heightSpathe shape‘Odessa’Leaf shapePlant heightNumber of inflorescencesSpathe colorSpathe shapeNumber of white leaf spots